Rotary engine.



No. 892,156. PATBNTED JUNE so, 1908.

R. HOFSTETTER.

ROTARY ENGINE.

APPLICATION FILED JU'LY 12,1906.

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4 Figlm No. 892,156. PATENTED JUNE so, 1908. R. HOFSTETTBR.

- ROTARY ENGINE.

APPLICATION FILED JULY 12,1906.

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PATENTED JUNE 30, 19 08.

'ROBERT HOFSTETTER, OF GENESEO, ILLINOIS.

ROTARY ENGINE.

Specification of Letters Patent.

Patented June 30, 1908.

Application filed July 12, 1906. Serial No. 325,948.

To all whom it may concern:

Be it known that I, ROBERT HoFs'rnTTnn, a citizen of the United States, residing at Geneseo, in the county of Henry, State of Illinois, have invented certain new and useful Improvements in Rotary Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Thisinvention has reference to improvements in rotary engines, and in particular to the means for projecting and withdrawing the piston-wings and for holding the same in such position during the rotation of the piston.

WVith this. end in view, the invention comprises the formation upon the inner face of one of the side plates of the cylinder, of a cam for projecting the piston-wings, and in the formation of a curved flange upon the interior surface of the central wall of the cylinder for retracting or withdrawing the wings.

The invention further includes the attachment of the above mentioned means to a rotary engine of the reversible type. v

The invention further comprises the novel construction, combination, and arrangement of the severalparts of the engine, all as hereinafter fully described, specifically claimed, and illustrated in the accompanying drawings, in which Figure 1 is a central section through the engine on a line at right angles to the engineshaft. Fig. 2 is an elevation of one of the side plates of the engine cylinder, showing the cam thereon. Fig. 3 is a section taken on the line 3 3 of Fig. 1. Fig. 4 is a similar view taken on the line l4 of Fig. 2. Fig. 5 is a view similar to Fig. 1 but showing the piston as provided with three wings instead of two. Fig. 6 is a similar view showing the above improvements as applied to a reversible engine, and showing also a slightly modified construction of the piston.

Like parts are designated by corresponding reference numerals in the several views.

Referring more particularly to the drawings, numeral 5 designates the engine base, upon which is adapted to be secured,in any desired manner, the engine cylinder 6, which latter includes side plates 7 and 8 and the central wall 9. The engine-shaft 10 is journaled to rotate in bearings formed in the side plates of the cylinder, and has keyed thereon the piston 11. The piston may comprise a hub connected to the engine-shaft and provided with a series of radiating arms and a rim or periphery carried by the arms, or, if desired, the piston may be solid. The latter construction, however, is shown in the drawings. The piston is provided with radiating Ways or openings 12, in which are mounted the movable wings 1S.

Formed upon the inner face of plate 7 is a cam 14, the engine-shaft passing through a suitable opening 15 therein. The greatest diameter of cam 14 is somewhat less than that of the piston, and the upper surface of said cam is approximately concentric with the piston and central wall of the cylinder. The central wall 9- of the cylinder is thickened to provide an integral shoulder or flange 16, disposed upon the inner face of said wall opposite the lower portion or edge of cam 14. The wings 13 of the piston are slightly greater in length than the piston and, when in their projected position, extend beyond the same at one side, traveling, when in such position, upon the outer edge of cam 14.

The engine cylinder is provided with an inlet-pipe 17 and an exhaust-pipe 18, connected with the main source of steam supply (not shown). Said pipes pass through the cylinder flange 16 to within a short distance of its inner edge, as shown.

The operation of the engine with the wings in the position shown in Fig. 1, is briefly as follows: On the admission of steam through the inlet-pipe 17, its impelling force and expansive action will serve to rotate the lower wing 13 to the left, the said wing being in its projected position through its own weight at this point. Upon reaching the upper surface of the cam, said wing will be held in such position and continues projected until the upper point of flange 16 is reached, which oint is approximately opposite that at whic 1 the decrease in diameter of the cam commences. The flan e will then tend to force said wing inwardl y within its opening 12 in the piston, and will hold the same in such position until the lowermost point of said flange is reached, the admission and exhaust of the steam taking place in the usual manner.

In Fig. 5 the piston is shown as provided with three arms or wings, arranged at equal distances apart, this construction permitting a quicker and easier start of the engine with out respect to the position of the wings.

The flange 16, however, in this construction occupies but one-third the inner face of the cylinder wall as opposed to the flange 16 of Fi s. 1 and 3, which occupies practically onehaf such surface. The drop of the lowermost wing of the piston, when the end of flange 16 is reached, is sudden and permits such wing to project its entire length, thus exposing a greater surface to the propelling action of the enteringsteam.

In Fig. 6, the cam and flange above described, are shown as applied to a reversible engine, the piston therein having, moreover, four wings'arranged at diametrically opposite points. The flange 16 is shown as directly beneath the engine-shaft instead of at one side thereof, the inlet and exhaust pipes 17 2 and 18 extending vertically therethrough. of a branch-pipe 20 with a main steam-supply pipe 19, and continue downward on each side of said latter pipe, as shown. Located withing the branch-pipe is a reversing valve 21, provided with a pair of plunger-heads 22 and operated by a lever 23.

The arrangement of the above parts is such that steam is admitted to one or the other of pipes 17 or 18 the plunger-heads 22 on the reverse valve 21 serving to cut ofl communication between the main steam pipe and the other of said pipes, which thus acts as the exhaust. The entering steam will strike the adjacent wing of the piston, causing a rotation thereof. The operating lever for the reverse valve is provided with the usual brake and segmental rack.

It will be noted from Fig. 6 that the upper face of flange 16 is formed on a double concave curve, and that the piston is flush against said flange at the point 24 where the inner ends of the concaves meet. Said flange is provided with a transverse opening 25 at this point, forming a seat in which is located a strip 26 of packing, normally held in contact with the piston face by means of a spring 27 secured in any manner in said seat.

Further description of the several parts of Said pipes communicate by means the engine and their operation will be unnecessary, in view of the above.

It will be understood that the reverse valve and its operating lever may, with equal readiness, be applied to the construction shown in Figs. 1 and 5, and that the piston may be provided with two, three or four wings, as desired.

Further changes and modifications may be made within the scope of the invention, and without sacrificing any of its advantages. It is not intended, therefore, that the invention be limited to the exact details of construction, shown and described.

What is claimed, is

A rotary engine comprising a cylinder ineluding side walls and a substantially cylindrical wall, a piston rotatably mounted within said cylinder, and radially disposed wings movable within said piston, the said side Walls being formed with like cam projections over the edges of which the wings ride and by which they are forced outwardly, the said cam projections having their edges of substantially spiral outline except for a portion of their extent throughout which they are directed radially, the radial edge portions of the projections being presented in a direction opposite to the direction of rotation of the piston, the inner face of the cylindrical wall being of like outline but with its abrupt l portion presented in opposition to the abrupt portions of the cam projections but located in a plane below and to one side of the same, there being a steam inlet port formed through the said cylindrical wall and opening through the abrupt portion of the inner face thereof, there being also an exhaust port formed through said wall and opening through the the abrupt portion of the said face.

In testimony whereof, I aflix my signature, in presence of two witnesses.

ROBERT HOFSTETTER. Witnesses:

HARRY A. REHERD, E. G. HARPER.

inner face thereof above and to one side of 

